Process for the production of compact, coarse sodium percarbonate

US4118466A · kind A · utility

Assignee

• Deutsche Gold- und Silber-Scheideanstalt Vormals Roessler

Inventors

• Hans Klebe · Rheinfelden (Baden), DE
• Gerd Knippschild · Bad Nauheim, DE
• Hubert Schuster · Rheinfelden (Baden), DE

Key dates

• Filing date: Sep 27, 1977
• Grant date: Oct 3, 1978
• Expiry date: Sep 27, 1997

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B15/103
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A compact, abrasion resistant sodium percarbonate is produced by reacting sodium carbonate with hydrogen peroxide. There is employed a solution saturated in sodium percarbonate and also containing (1) sufficient sodium carbonate that there is present sodium carbonate decahydrate as a solid phase, (2) sodium chloride in an amount of 100 to 200 grams per liter, (3) an active oxygen stabilizer and (4) sodium hexametaphosphate in an amount of 0.1 to 1.9 grams per liter. There is added hydrogen peroxide in an amount about equivalent to the dissolved sodium carbonate which results in a supersaturated solution of sodium percarbonate. The supersaturation is broken down by precipitation of sodium percarbonate during the addition of the hydrogen peroxide and up to 60 minutes thereafter. The entire process is carried out at a substantially constant temperature within the range of 10.degree. to 20.degree. C. The precipitated sodium percarbonate is separated and dried and the mother liquor can be returned to the first step of the process.